Synthetic fibers are typically manufactured to attain a particular level of performance depending on the intended use of the resulting fibers. Since synthetic fibers are generally manufactured from synthetic polymers or small molecules, the mechanical properties of these fibers may depend on the properties of the polymers or molecules used and the methods used to manufacture the fibers.
For example, the strength of a typical fiber generally increases with a decrease in the diameter of the fiber. Examples fibers that may exhibit this phenomenon can include whiskers, polymer, carbon, glass, and ceramic fibers. The mechanism that may cause the increase in strength varies, but can include improvements in material structure and orientation as well as a reduction in the size and/or quantity of defects in the material structure. As a result, advanced fiber manufacturers usually adopt the smallest fiber diameter that is technologically and economically feasible. However, all existing advanced (structural) fibers are brittle—i.e. they break at small failure strains, thus absorbing relatively low energy to failure. In addition, fibers prepared by conventional mechanical spinning techniques are limited in diameter range. The latest generation of carbon fiber, the smallest commercially available continuous fiber today, has diameter about 4.5 micrometers. A fiber that is simultaneously strong, stiff, and tough may be beneficial for most structural applications, especially so for safety critical applications.